A security report by the by the UN Department on Safety and Security (UNDSS), which was seen by Reuters, stated: "These districts have severely been affected by the ongoing stories of blood sucking and possible existence of vampires."

The UNDSS report said the rumours of vampirism had started in neighbouring Mozambique although it was not clear how. It recommended the "temporary suspension of UN activities in the area until the situation is normalised".

The acting UN resident coordinator, Florence Rolle, said some staff had moved while others remained in the districts depending on where their operations were taking place.

"UNDSS is continuing to monitor the situation closely to ensure all affected UN staff are back in the field as soon as possible," Rolle told Reuters.

Malawian president, Peter Mutharika, said the reports were "distressing and agonising".

"This development has been of grave concern to the president and the entire government," his office said in a statement.